Remove extra cart header row from admin pages, use shared post header

Cart admin pages (admin overview, payments) now use the same header
pattern as blog/market/events: root_header → post_header → admin_header.
The domain name appears via app_label on the root header instead of a
separate level-1 "cart" row.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cart/sexp/sexp_components.py

@@ -13,6 +13,7 @@ from markupsafe import escape
 from shared.sexp.jinja_bridge import render, load_service_components
 from shared.sexp.helpers import (
     call_url, root_header_html, post_admin_header_html,
+    post_header_html as _shared_post_header_html,
     search_desktop_html, search_mobile_html, full_page, oob_page,
 )
 from shared.infrastructure.urls import market_product_url, cart_url
@@ -25,6 +26,25 @@ load_service_components(os.path.dirname(os.path.dirname(__file__)))
 # Header helpers
 # ---------------------------------------------------------------------------
 
+def _ensure_post_ctx(ctx: dict, page_post: Any) -> dict:
+    """Ensure ctx has a 'post' dict from page_post DTO (for shared post_header_html)."""
+    if ctx.get("post") or not page_post:
+        return ctx
+    ctx = {**ctx, "post": {
+        "id": getattr(page_post, "id", None),
+        "slug": getattr(page_post, "slug", ""),
+        "title": getattr(page_post, "title", ""),
+        "feature_image": getattr(page_post, "feature_image", None),
+    }}
+    return ctx
+
+
+def _post_header_html(ctx: dict, page_post: Any, *, oob: bool = False) -> str:
+    """Build post-level header row from page_post DTO, using shared helper."""
+    ctx = _ensure_post_ctx(ctx, page_post)
+    return _shared_post_header_html(ctx, oob=oob)
+
+
 def _cart_header_html(ctx: dict, *, oob: bool = False) -> str:
     """Build the cart section header row."""
     return render(
@@ -727,6 +747,7 @@ def _cart_page_admin_header_html(ctx: dict, page_post: Any, *, oob: bool = False
                                   selected: str = "") -> str:
     """Build the page-level admin header row — delegates to shared helper."""
     slug = page_post.slug if page_post else ""
+    ctx = _ensure_post_ctx(ctx, page_post)
     return post_admin_header_html(ctx, slug, oob=oob, selected=selected)
 
 
@@ -772,24 +793,16 @@ def _cart_payments_main_panel_html(ctx: dict) -> str:
 async def render_cart_admin_page(ctx: dict, page_post: Any) -> str:
     """Full page: cart page admin overview."""
     content = _cart_admin_main_panel_html(ctx)
-    hdr = root_header_html(ctx)
-    child = _page_cart_header_html(ctx, page_post) + _cart_page_admin_header_html(ctx, page_post)
-    hdr += render("cart-header-child-nested",
-                  outer_html=_cart_header_html(ctx), inner_html=child)
-    return full_page(ctx, header_rows_html=hdr, content_html=content)
+    root_hdr = root_header_html(ctx)
+    post_hdr = _post_header_html(ctx, page_post)
+    admin_hdr = _cart_page_admin_header_html(ctx, page_post)
+    return full_page(ctx, header_rows_html=root_hdr + post_hdr + admin_hdr, content_html=content)
 
 
 async def render_cart_admin_oob(ctx: dict, page_post: Any) -> str:
     """OOB response: cart page admin overview."""
     content = _cart_admin_main_panel_html(ctx)
-    oobs = (
-        _cart_page_admin_header_html(ctx, page_post, oob=True)
-        + render("cart-header-child-oob",
-                 inner_html=_page_cart_header_html(ctx, page_post)
-                 + _cart_page_admin_header_html(ctx, page_post))
-        + _cart_header_html(ctx, oob=True)
-        + root_header_html(ctx, oob=True)
-    )
+    oobs = _cart_page_admin_header_html(ctx, page_post, oob=True)
     return oob_page(ctx, oobs_html=oobs, content_html=content)
 
 
@@ -800,26 +813,16 @@ async def render_cart_admin_oob(ctx: dict, page_post: Any) -> str:
 async def render_cart_payments_page(ctx: dict, page_post: Any) -> str:
     """Full page: payments config."""
     content = _cart_payments_main_panel_html(ctx)
-    hdr = root_header_html(ctx)
+    root_hdr = root_header_html(ctx)
+    post_hdr = _post_header_html(ctx, page_post)
     admin_hdr = _cart_page_admin_header_html(ctx, page_post, selected="payments")
-    child = _page_cart_header_html(ctx, page_post) + admin_hdr
-    hdr += render("cart-header-child-nested",
-                  outer_html=_cart_header_html(ctx), inner_html=child)
-    return full_page(ctx, header_rows_html=hdr, content_html=content)
+    return full_page(ctx, header_rows_html=root_hdr + post_hdr + admin_hdr, content_html=content)
 
 
 async def render_cart_payments_oob(ctx: dict, page_post: Any) -> str:
     """OOB response: payments config."""
     content = _cart_payments_main_panel_html(ctx)
-    admin_hdr = _cart_page_admin_header_html(ctx, page_post, selected="payments")
-    oobs = (
-        _cart_page_admin_header_html(ctx, page_post, oob=True, selected="payments")
-        + render("cart-header-child-oob",
-                 inner_html=_page_cart_header_html(ctx, page_post)
-                 + admin_hdr)
-        + _cart_header_html(ctx, oob=True)
-        + root_header_html(ctx, oob=True)
-    )
+    oobs = _cart_page_admin_header_html(ctx, page_post, oob=True, selected="payments")
     return oob_page(ctx, oobs_html=oobs, content_html=content)